Method of producing semiperforated sifter openings in containers



April 23, 1957 I R. J. CRAWFORD ET AL METHOD OF PRODUCING SEMIPERFORATED SIFTER OPENINGS IN CONTAINERS Filed June 6, 1955 INVENTORS ROBERT J. CRAWFORD FRANK ALFIERI BY ,ZM 2715M wean 4%. MM

ATLO RN EYS United rates Patent NIETHOD 0F PRODUCING SEMIPERFORATED SIFTER OPENINGS IN CONTAINERS Robert J. Crawford, Lincroft, and Frank Alfieri, Jersey City, N. .L, assignors to American Can tlompany, New York, N. Y., a corporation of New Jersey Application June 6, 1955, Serial No. 513,296

Claims. (Cl. 113-116) The present invention relates to cans or containers having semiperforated potential sitter openings for dispensing scouring powder and the like materials and has particular reference to a method of producing the semipcrforated potential sifter openings in the cans or containers.

Cans or containers for scouring powder and the like materials usually are fitted with top end closure members provided with semiperforated sitter openings, i. e. potential openings defined by deep score lines or wholly cut through slits leaving a plug or a plurality of plugs which may be readily punched out to permit dispensing of the container contents as by a sifting action. In some cases the slit may be continuous so that when the plug defined thereby is punched out it is completely separated from the container. In other cases the slit may be broken, interrupted by integral bridge portions, so as to leave the plug partially attached to the container so that it is merely bent inwardly when punched through to provide an opening.

In any case it has been found that with the new finely ground powders, considerable sifting takes place through the slits of the unopened containers during shipment and other handling prior to purchase by the consumer. Experimentation shows that this sifting takes place through any slit that shows light through it, no matter how fine or narrow the slit and in order to prevent the undesired sifting the slit must be closed so tightly that light will not show through.

It is an object of the instant invention to overcome this difiiculty by the provision of a method of defining semiperforated sifter openings by slitting through a wall of a can or container and closing the resulting slits so tightly that light cannot penetrate through the slits so as to thereby prevent the escape of the contents of the container through the slits by a sifting action.

Another object is the provision of such a method of producing nonsiftable semiperforated potential openings in a container so that the wall of the container containing the potential openings may be maintained in a clean con dition free of sittings prior to the purchase of the container by the consumer.

Another object is the provision of such a method which may be carried out by existing automatic machinery at.low cost and high speed production with highly efilcient results.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying-drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

Figure l is a perspective view of a sealed container provided with semiperforated potential sifter openings in accordance with the steps of the instant method invention;

Fig. 2is' an enlarged plan view of the top of the conr 2,789,524 Ice Patented Apr. 23, rasv tainer shown in Fig. 1, showing the potential sifter openings therein;

Fig. 3 is an enlarged sectional view taken substantially along the broken line 33 in Fig. 2 and showing one of the potential openings punched out to permit dispensing of the container contents therethrough;

Fig. 4 is an enlarged plan view of a portion of the container top showing one of the potential openings in detail in a partially formed condition as a result of an initial forming operation;

Fig. 5 is a sectional view taken substantially along the line 55 in Fig. 4;

Fig. 6 is a view similar to Fig. 5, the view showing forming elements in section and in the process of effecting an initial forming operation to produce the potential openings, parts being broken away;

Fig. 7 is a sectional view of a potential opening as taken substantially along the line 77 in Fig. 4, the view also showing forming elements in section, parts being broken away;

Fig. 8 is a sectional view taken substantially along the line 8-8 in Fig. 6;

Fig. 9 is a sectional view of a portion of the container top including a potential opening and forming elements in the process of performing a final step in the formation of the openings; parts being broken away; and

Fig. 10 is an enlarged sectional view showing a modification in the method of producing the potential openings shown in Figs. land 2.

As a preferred or exemplary embodiment of the instant invention the drawings illustrate the steps of forming semiperforated potential sifter openings A in a sheet metal top B of a composite container C having a fibre body D for holding and dispensing scouring powder and the like substances. The top B preferably is made of tin plate, black iron or the like material. A plurality of the potential sitter openings A are formed in the top B in any desirable design such as the ring design illustrated in Fig. 2.

The semiperforated potential sifter openings A preferably are circular in configuration and constitute a disc like member or plug 20 defined by a plurality of short curved or arcuate slit lines 21 (Fig. 2) which terminate in narrow uncut connecting links or bridges 22 which connect the plug 20 with the surrounding material of the container top B. The bridges 22 are approximately forty five thousandths of an inch wide and are easily broken through when desired to release or sever the plug the plug 20 still connected to the container top by its hinge bridge 23 is bent inwardly as shown in Fig. 3 to produce a clear sifter opening 24 through which the container contents may be readily dispensed.

The method of producing these potential sifter openings A will now be described and explained. The main purpose of this method as hereinbefore mentioned is to produce the opening defining slit lines 21 in such a manner that they are so tight that light will not show through them so that they will restrain the container contents and thereby prevent sifting of the contents to the top of the container during shipment and other handling prior to opening.

In accordance with the preferred steps of this method invention the container top B for each potential opening A is first formed with a struck out or depressed countercut through or slit to provide-the slit lines 21. This slitting of the wall 26 may be efiected at any place along its length but preferably as shown in the drawings is effected near the base or outer edge of the panel 25. The slit may be continuous as to completely sever the panel 25 from the container top B or may be interrupted as shown in the drawings to provide the bridges 22 and/ or the hinge bridge 23 to retain a connection between the panel 25 and the container top B.

Also the forming of the countersunk paneli25 and its surrounding wall 26 and the slitting of the beveled countersink wall 26 may be effected as separate steps'or as shown in the drawings may be effected simultaneously. For effecting these operations the drawings illustrate one form of, apparatus which comprises a vertically movable punch 31 (Figs. 6 and 7) and a stationary annular die 32 between which the container top B is placed. The punch 31 is cylindrical in shape having a flat lower end and an outside diameter substantially equal to the diameter of the panel 25. At spaced intervals around its periphery the punch 31 is formed with vertical clearance grooves 33 (Fig. 8) to leave portions of the top Buncut to provide for the formation of the narrow bridges 22 and'the wide bridge 23.

The annular die 32 preferably is provided'with afiat top 35 for supporting the containertop B' and is further provided with a circular cutting edge 36"surroundi1ig a clearance opening 37 of a diameter substantially equal to the outside diameter of the punch 31 for cooperation therewith. The cutting edge 36 preferably is depressed below the top of the die 32 and forms the terminal edge of an inwardly beveled seat 38 which surrounds the mouth of the clearance opening 37 and extends from the top 35 of the die to the cut edge 36.

When the container top B is placed on top of the annular die 32 and the punch 31 is moved down into the 40 die a predetermined distance, just below the cut edge36, the flat lower end of the punch, engaging against the container top B, pushes the'portion of the top B under the punch down into the die to form the countersunk panel 25. This same punch 31 simultaneously draws or stretches the material surrounding the panel 25 downwardly over the beveled seat 38 of the die to form the beveled countersink wall 26. The drawing action elongates the material in the wall 26'and thereby provides what is termed an excess ofmaterial surrounding the"* panel 25.

This drawing action continues as the punch 31 descends into the die, until it reaches the cut edge 36. At'this point in its downward travel'the outer edge of the punch the drawn material at the base of the beveled countersink wall 26 and thus forms the slits 21 of the potential sifter opening A. The clearance grooves 33in the punch 31 leaves the drawn material in this area uncut or 'unslit and thereby produces the bridges 22, 23. This completes the panel forming and the countersink wall slitting operations and thepunch is thereupon withdrawn to permit removal of the container top B from the device.

As the next step in the method, the depressed panel 25 and the elongated, beveled countersink wall 26 are pushed back into the plane of the surrounding material of the container top B as best shown in Fig. 9. In thus pushingthe panel 25 and elongated wall 26 back into the plane of the container top B the elongat d or exc'essmaterial in the beveled countersink wall 26 is compressed the" space'occupiedby 'the originalundrawn material and thereby provides an excess of material to be compressed against the edge of the panel 25.

Hence as a result of this elongation of the original material and the compressing of it back into its original space in the plane of the container top B, the slit edge of the bevel wall 26 is forced into so tight an engagement with the slit edge of the panel 25 that light cannot and does not penetrate through the slit and hence'the Slit'is tightly enough closed to prevent inadvertent sifting of the container contents through the slit to the adjacent top surfaces of the container top B. This operation preferably is performed through -a singleha'mmerblow against the panel 25 as by a bumping device such as the hammer 41 and anvil 42 shown in Fig. 9.

In its new pushed back position in the plane of the container top B, the panel 25 now constitutes the removable or severable plug 20 and is fully prepared for protecting the container contents during shipment and storage and may be readily knocked out to produce the opening 24 (Fig. 3) to permit dispensing of the contents.-

' around the panel for compression against the slit edge of the panel to make the punch-out plug 20 1eakproof. This same result may be obtained by initially reforming'or displacing a portion of the container top material around and immediately adjacent the panel 25 as by the formation 1 of a head 45 shown as a modified form of the invention illustrated in Fig. 10. In this form of the invention the panel 25 remains in the plane of the container top B and only the material around the panel is displaced to produce the excess material.

a The slits 21 which sever or partially sever the panel 25 from the container top B are made in a manner as shown in Fig. 7, in the head 45, preferably near the inner base of the bead adjacent the panel as shown in Fig. 10. Hence when the bead 45 is compressed back into the plane of the container top B by the step illustrated in Fig. 9 the excess material in the head is forced tightly against the slit edge of the panel as in the preferred form ofthe invention to tightly close the slit or slits 21 against the penetration of light therethrough with the result that the slits 21 are leakproof against sifting of the containercontents therethrough. I

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description,and it will be apparent that various-changes may be I g i made in the steps of the method described and theirorder in cooperation with the cut edge 36 cuts through or sllts of accomplishment without departing from the spirit and scope "of 'theinvention or sacrificing all of its material advantages, the method hereinbefore described being mere- 1y a preferred embodiment thereof.

' We claim:

1. A' method of producing a partially perforated potential sifter opening in a container, comprising the steps of reforming a portion of a wall of a container to define an'area' substantially surrounded by said reformed portion and to provide an excess of wall material around said area, cutting the reformed portion of said wall at least partially around said area to provide a slit between said area and said container wall, and compressing said reformed slit wall to force the excess of wall material into tight edgewise engagement with said area to close said slit against sifting of the contents of the container therethrough and to'set oif in said wall a punch-out plug for dispensingsaidcom term from said container.

2; A method of producing a partially perforated potential sifter opening in a container, comprising the'ste'ps of displacing a portion of a wall of a container out' of the plane of said wall to define a panel substantially surrounded by said displaced portion and to provide an excess of wall material around said panel, cutting said displaced portion of said wall at least partially around said panel to provide a slit between said panel and said container wall, and compressing said displaced slit wall back into the plane of said container wall to force the excess of wall material into tight edgewise engagement with said panel to close said slit against sifting of the contents of the container therethrough and to set off in said wall a punch-out plug for dispensing said contents from said container.

3. A method of producing a partially perforated potential sifter opening in a container, comprising the steps of forming in a wall of a container a panel countersunk out of the plane of said container wall and having a surrounding drawn countersink wall connecting said panel with said container wall, cutting through said drawn countersink wall to sever said panel at least partially from said countersink wall to provide a slit between said panel and said countersink wall, and compressing said panel and said adjacent countersink wall back into the plane of said container wall to force the severed edges of said panel and said countersink wall into tight edgewise engagement to hold said panel in place as a punch-out plug and to exclude the penetration of light and the sifting of the container contents past said engaged edges.

4. A method of the character defined in claim 3 wherein said drawn countersink wall is inclined inwardly and is cut through at its base to form a slit between said countersink wall an said panel.

5. A method of the character defined in claim 1 wherein said reformed portion is in the form of a bead projecting from the plane of said container wall.

References Cited in the file of this patent UNITED STATES PATENTS 1,128,532 Schmidt Feb. 16, 1915 1,295,168 Hooker Feb. 25, 1919 2,059,671 Steenweg Nov. 3, l936 2,444,268 Peters June 29, 1948 

